The present invention relates generally to electrophotographic and other document printing devices, and more particularly to an open architecture device usable downstream from an electrophotographic or other printing or document reproduction apparatus for performing various post-processing operations on the documents output from the printing apparatus.
Electrophotographic printing and reproduction devices are well known. Typically, a photoconductive member is charged to a uniform potential and thereafter exposed to a light image of an original document to be reproduced. The exposure discharges the photoconductive member in areas corresponding to the background of the document being reproduced and creates a latent image on the photoconductive member. Alternatively, in a laser-beam printer or the like, a light beam is modulated and used to selectively discharge portions of the photoconductive member in accordance with image information. With either type of apparatus, the latent image on the photoconductive member is visualized by developing the image with a developer powder commonly referred to as "toner." Most systems employ developer which comprises both charged carrier particles and charged toner particles which triboelectrically adhere to the carrier particles. During development of the latent image, the toner particles are attracted from the carrier particles by the charged pattern of image areas on the surface of the photoconductive member to form a visualized toner image on the photoconductive member. This toner image is then transferred to a recording medium such as paper or the like for viewing by an end user. Typically, the toner is fixed to the surface of the paper through the application of heat and pressure.
Following the successful reproduction of one or more documents in this fashion, it is often desirable to perform one or more of a wide variety of post-processing functions on the printed documents. For example, certain applications require the selective addition of color or other enhancements to the printed documents using ink jet annotation or the like, application of magnetic ink character recognition media, job/document serial number and account auditing, insertion of pages into the printed documents, brail embossing, perforation, slitting, envelope stuffing, and postage metering. Heretofore, the post-processing functions could be carried out off-line with one or more dedicated post-processing devices. Of course, the off-line devices were specially designed to perform certain specific post-processing functions. The performance of other post-processing functions necessitated the replacement of some or all of these off-line devices in their entirety, including all of the base document handling and other hardware thereof. Other post-processing devices are designed to work on-line with a electrophotographic printing apparatus. Like the off-line devices, these on-line devices have been limited to specific functions, and must also be completely replaced in the event an end-user desires to perform different post-processing operations.
Accordingly, a need has been recognized for a post-printer open-architecture device capable of performing any of a wide variety of post-processing functions using the same base document handling hardware, but also releasably receiving one or more post-processing modules that perform particular post-processing functions. The subject invention is deemed to meet the foregoing needs and others, and to provide an open-architecture post-processing device that demonstrates better and more advantageous overall results.